Signal controlling apparatus



Patented Apr. 30, 1935 g I v v I UNITED-STATES PATENT OFFICE ApplicationDecember 12, 1929, Serial No. 413,505 Renewed October 3, 1934 7 Claims.(Cl. 177-329) This invention relates to improved signal ac- Accordinglyoperation of this device depends upon tuating devices and moreparticularly to arrangetransmission of pressure through the continuousments for operating trafllc signals. surface layer rather than involvingthe provision It has heretofore been proposed to arrange to of aseparate independently movable strip in the operate automatic trafficsignals by means of movroadway. Accordingly, I preferably arrange. an 6able elements located in the roadways at a diselongate metal receptaclebeneath the surface of tance from an intersection, each of theseelements the right-hand portion of a roadway adjoining being depressibleby a vehicle passing over the an intersect-ion, the thickness of thewall of the same, to close a switch which forms part of a; receptaclebeing so determined in relation to its 10 system for energizing thetraffic lights. An ardepth in the roadway and its width that it may 10'rangement of this character ordinarily has necesbe susceptible topressure .resulting from the sitated the provision of some factor foreffecting movement of vehicles over the same in such a the continuedenergization of the light as the-ve manner that such increases inpressure will be hicle passes between the movable actuating e1e-'effective to decrease the volumetric capacity of ment and theintersection. Furthermore the dethe receptacle-0r to increase thepressure 01 16 pressible elements disposed in the roadway have uid orfluid contained therein. Preferably such been unsatisfactory andundependable due to the fluid is relatively non-compressible and extendspossibility of material such as dust or mud lodg thro a Suitable duet toa current cl i ing upon or between the moving parts and previce so thatthe increase in pressure applied to 20 venting the normal operationthereof, as well as the receptacle will close a circuit to ener- 20 dueto the effect of surface moisture, snow or gize the signal light at thevehicular in the like and also due to the likelihood of thecontersection. Preferably this device may comprise ventional streetcleaning appliances detrimentally a trap connected to the liquidcontaining reaifecting mechanism of this character. ceptacle andcontaining a current-conductive liqv The present invention affords meanswhich uid such as mercury, S thet p e -l p 25 may be arranged below thesurface of the roadtien of Pressure to receptacle, the rcu y way andwhich may be self-contained orfully ,r S in e g 0 the p to PermitCurrent enclosed; accordingly the system need not be subt D35 betweenSuitable immersed Contacts, thus jected to the adverse variantconditions of moisclesing'the c rcu t w ich cludes t e appropriture,dust, and mechanical attrition of all sorts ate Signal g Pl'eferably I3150 Provide means 30 which occurs at the surface of the roadway. Furfop i t g t device automatically to C thermore, the controlling factor forthis device pen-sate fer gradual Changes in temperature may be elongateand disposed longitudinally of a and/or pressure, although these changesare not roadway, thus affording means that may continulikely to begreat, when the liquid containing ally be actuated by a vehicle until itreaches the receptacle is located below the surface of the 35intersection and thereby permitting the continued roadway. energizationof a signal light or the like without In the accompanying drawing:necessity for a special delay factor, secondary Fig. 1 is a somewhatdiagrammatic view ofa relays or timing mechanisms or the like. vehicularintersection showing my improved sig- 40 In order to accomplish thisresult, I preferably nal controlling devices arranged in relation 40arrange a pressure sensitve receptacle at a suitthereto; able depthbelow the surface of the roadway, hav- Fig. 2 is a sectional viewsomewhat diagraming found that the weight of an ordinary vehicle maticin character indicated by line 2-2 of Fig. will cause an appreciableincrease in pressure 1; and

at a distance belcw the vSurface o h adw y Fig. 3 is a sectional detailofthe current-clos- 45 or pavement. In accordance with this invenmg dvic r switch. tien, the roadway s in t e m of a pavement In accordancewith this invention, a suitable ha a surface layer providing acontinuous receptacle I may be disposed beneath the surface unbrokensurface, such as for example is affordof the roadway 2 at any desiredpoint, as for ed by a conventional concrete or macadam pavew exampleadjoining an intersection 3. The recep- 50 ment. Such a layer thereofaffords the same tacle may comprise transversely curved upper characterof continuous surface over the device and lower sheet members 4 and 5respectively as in other parts of the roadway, there being no that haveflanges 6 welded or otherwise secured definite breaks in the surface tocorrespond to to each other to provide a fluid-tight construc- 5 thelocation of the device beneath its surface. tion. Preferably, as shownin Fig. 1, the recep- 5 in relation to the roadway and extending from apoint spaced from the intersection substantially to the intersection,and the thickness of its walls is so determined in relation to the depthof installation and the character of pavement and sub-soil that it willbe slightly distorted by the weight of a vehicle passing over it.

A tube ID of small diameter may be connected to the receptacle and havean upward continuation H which communicates through a minute opening 12with a reservoir IS. A suitable breather tube it? permits the surface ofthe liquid, such as oil, in reservoir 15 to be subject to atmosphericpressure. A downwardly extending portion of the tube It) forms one legof atrap i! which normally contains an electrically conductive liquidsuch as mercury.

Preferably the opposite leg of this trap is provided with a pair ofconductors 23 and 24 which are connected by leads 25 and 26 to asuitable signal appliance, which in the accompanying drawing for thepurposes of illustration is illustrated as a simple warning or signalinglight 21, but which obviously may be any suitable system ofelectro-magnets, relays or the like, as desired. A breather 29 alsopermits the leg of trap I! which contains the contacts to communicatewith the atmosphere; thus the pressure at opposite sides of the trap maybe equalized.

It is evident that a vehicle passing over the roadway 2 will cause asuflicient increase in the pressure applied to the top of receptacle Islightly to flatten the same with a consequent decrease in itsvolumetric capacity, thus forcing fluid through tube 10 and causing themercury in trap H to rise so that both of the conductors are immersedtherein and-thereby closing the circuit between leads 25 and 26. Sinceorifice I2 is of very restricted diameter, such a relatively suddensurge of the liquid through tube ill will not cause enough flow throughorifice 12 to result in an appreciable rise in the liquid level inreservoir i5, nor will such flow occur during the length of timenormally required by a vehicle to pass over receptacle l.

Obviously as soon as the vehicle leaves the receptacle, the latter tendsto return to its normal shape and the mercury will return to theposition illustrated in Fig. 2, wherein it has a substantially equalheight in each of the legs of trap'l 'l.

If there is a permanent change in the pressure applied to the receptacleor a change in its temperature results in a tendency of the liquid inreceptacle 1 permanently to expand or contract,

opening l2 will permit gradual extrusion of liquid to compensate forsuch a change, thus permitting the mercury in trap II toretain'itsnormal position except when displaced by the weight of apassing vehicle. As shown, receptacle I may be permanently installed inthe earth beneath the roadway and accordingly ordinarily will notinvolve any necessity for frequent attention adjustment or care. Thereceptacle i2 and the trap I! may be conveniently located in a suitablecontainer 40 that may be disposed at any desired point, but which may bearranged to permit convenient access to these parts should the same benecessary and to permit the convenient exposure of the surfaces of theliquids in chamber l2 and trap I! to atmospheric pressure.

While for convenience or illustration I have shown a typical example ofmy signal operating means as connected to a single signal or warningtacle is elongate, being longitudinally disposed light it is evidentthat it may be arranged to operate any desired type of mechanism throughthe medium of an electrical controlling apparatus or the like. Ifdesired, a plurality of round or circular receptacles may be substitutedfor the single elongate receptacle illustrated herein. Each of the samebeing connected in parallelto the same elongate circuit so that avehicle passing toward the intersection continues to actuate thesignalling device by successfully increasing the pressure to which thereceptacles are subjected; it is further evident that in the case of awide roadway it may be preferable to arrange two or more of thereceptacles side by side in order to permit the energization of thesignal device by a vehicle which is disposed overany part of theright-hand side of the roadway adjoining the intersection.

I claim:

1. In a combination including a roadway having a continuous unbrokensurface and a device operable in response to the passage of a vehicleover the roadway, an actuating mechanism comprising means disposedentirely beneath the continuous surface of said roadway for effectingthe actuation of said device, said means being operable in response todeflection of said surface by a vehicle passing over the roadway abovesaid means.

2. In a combination including a roadway having a continuous unbrokensurface and a device operable in response to the passage of a vehicleover the roadway, an actuating mechanism comprising a distortable bodydisposed entirely beneath the continuous surface of said roadway, andmeans operable in response to distortion of said body by a vehiclepassing over the roadway adjacent to that part containing said body foreffecting the actuation of said device.

3. In a combination including a roadway having a continuous unbrokensurface and a device operable in response to the passage of a vehicleover the roadway, an actuating mechanism comprising an elongatecompressible body disposed longitudinally in relation to the extent ofthe roadway and entirely beneath its continuous surface, said body beingcompressed by the weight of a vehicle passing over the roadway a jacentto that part beneath which it is dispersed, and means responsive tocompression of said body for actuating said device.

4. In a combination including a roadway having a continuous unbrokensurface and a device operable in response to the passage of a vehicleover the roadway. an actuating mechanism comprising an elongateliquid-containing receptacle disposed longitudinally in relation to theextent of the roadway and entirely beneath its continuous surface, saidreceptacle being distortable by a vehicle passing over the roadwayadjacent to that part beneath which it is disposed, a duct connected tothe receptable, and means operable in response to the flow of liquidthrough said duct for efiecting the actuation of said device.

5. In a combination including a roadway having a. continuous unbrokensurface and a device operable in response to the passage of a vehicleover the roadway, an actuating mechanism comprising a fluid-containingreceptacle disposed entirely beneath the continuous surface of theroadway and distortable by the weight of a vehicle passing over theroadway adjacent to that part ing a continuous unbroken surface and adevice operable in response to the passage oi a vehicle over theroadway, an actuating mechanism comprising a fluid-containing receptacledisposed entirely beneath the continuous surface of the road,- way anddistortable by the weight of a vehicle passing over the roadway adjacentto that part containing the receptacle, a duct connected to thereceptacle, and means operable in response to the flow of fluid throughsaid duct for actuating said device, and compensating means forpreventing a gradual change in pressure from caus ing a fluid flow insaid duct sufliclent to actuate said device. I

7. In a combination including a roadway having a continuous unbrokensurtace and a device operableinresponsatothepassageotavehicle over theroadway, an actuating mechanism comprising a fluid-containing receptacledisposed entirely beneath the continuous surface or the roadway anddistortable by the weight or a vehicle passing over the roadway adjacentto that part containing the receptacle, a duct connected to thereceptacle, and means operable in response to the flow 0t fluid throughsaid duct tor actuating said device, and compensating means comprising areservoir connected to said duct by a passage of restricted size,whereby a gradual change in pressure or long continued application ofpressure is prevented from causing an accidental or continuedoperationof said device.

nears v. measmzv.

